When you enable "This project is parameterized" option and provide Password Parameter for example with name PASS and default value Pass$$ dollar sign get escaped by Jenkins to Pass$. 

This is the pipeline script

timeout(20) {
    
   node('agent-maven-python') {
	stage('bash') {
		sh '''
                echo $PASS
                echo ''' + PASS + '''
	       '''
	}
   }
}

This is the output, it is missing the second $ sign. I haven't found other escaped symbols . Jenkins version jenkins-2.138.4

+ echo 'Pass$'
Pass$
+ echo 'Pass$'
Pass$

 This also affects simple println

timeout(20) {
    
node() {
	stage('Sample bash') {
	    println env.PASS
	}
}
}